[sheepdog-users] How much spaces is used by snapshots?

[Liu Yuan]

On Mon, Jul 08, 2013 at 08:59:45AM +0200, Valerio Pachera wrote:
> Considering this vdi list
> 
>   Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag
> s backup_data     2  1.0 TB  4.7 GB  195 GB 2013-07-04 08:52   c8d129
>    2         lug04
> s backup_data     3  1.0 TB  118 GB  102 GB 2013-07-04 09:59   c8d12a
>    2
> s backup_data     4  1.0 TB  115 GB  107 GB 2013-07-05 16:42   c8d12b
>    2         lug08
>   backup_data     0  1.0 TB  0.0 MB  222 GB 2013-07-08 08:33   c8d12c     2
> 
> how do I calculate the amount of space used the snapshots?
> What I mean is that keeping snapshots should have an impact on the
> cluster available size.
> Soon or later I'll fill up the cluster if I don't remove snapshots.
> I would like to monitor that.
> 
> I tried to delete older snapshot and check if anything was changing in
> vdi info, and it didn't
> 
> # collie node info
> Id      Size    Used    Avail   Use%
>  0      2.4 TB  298 GB  2.1 TB   11%
>  1      2.4 TB  290 GB  2.2 TB   11%
>  2      2.9 TB  354 GB  2.5 TB   11%
>  3      2.3 TB  300 GB  2.0 TB   12%
> Total   10 TB   1.2 TB  8.8 TB   12%
> Total virtual image size        1.3 TB
> 
> # collie vdi delete -s 2 backup_data
> 
> # collie node info
> Id      Size    Used    Avail   Use%
>  0      2.4 TB  298 GB  2.1 TB   11%
>  1      2.4 TB  290 GB  2.2 TB   11%
>  2      2.9 TB  354 GB  2.5 TB   11%
>  3      2.3 TB  300 GB  2.0 TB   12%
> Total   10 TB   1.2 TB  8.8 TB   12%
> Total virtual image size        1.3 TB

Current algorithm only release space after all the snapshots and its clones are
deleted. Kazutaka has a patch set in progress to release objects once they are
not referenced by any snpashots & clone & working vdi. After this patch set get
merged, deletion of snapshots will make effect of reduction of used space.

Thanks
Yuan